ARS | Publication request: Factors affecting the alkaline cooking performance of selected corn and sorghum hybrids

Submitted to: Cereal Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: August 2, 2010
Publication Date: November 1, 2010
Citation: Johnson, W.B., Ratnayake, W.S., Jackson, D.S., Lee, K., Herrman, T.J., Bean, S. and Mason, S.C. 2010. Factors affecting the alkaline cooking performance of selected corn and sorghum hybrids. Cereal Chemistry. 87(6):524-531.

Interpretive Summary: A major food use of dent corn (Zea Mays L.) and sorghum (Sorghum bicolor L. Moench) is in the commercial production of tortillas, snack chips, and related foods through the traditional alkaline cooking process known as nixtamalization. Understanding which kernel characterization tests are predictive of nixtamalization performance would aid in developing better methods for selecting grain for processing. These methods may include development of predictive equations based on a few characterization tests or the creation of classification schemes that would allow processors to assign a particular lot of grain as best for nixtamalization or some other use. We found that characteristics such as kernel hardness, moisture content, starch and protein content were important factors related to nixtamal moisture content. Location and hybrid factors influenced most kernel characteristics and nixtamalization processing variables. Identifying sample growing locations would aid in screening samples for nixtamalization.

Technical Abstract: Dent corn (Zea mays L.) and sorghum (Sorghum bicolor L. Moench) sample sets representative of commonly grown hybrids and diverse physical attributes were analyzed for nixtamalization performance. The influence of kernel characteristics including hardness, density, starch properties (thermal, pasting, and crystallinity), starch content, protein content, and prolamin content on nixtamalization performance was also determined. Corn nixtamal moisture content was lower for hard, dense kernels with high protein contents; sorghum nixtamal moisture content was lower for kernels with low moisture contents and low starch relative crystallinities. Significant regression equations showed that corn nixtamal moisture content was influenced by TADD (tangential abrasive dehulling device) index, kernel moisture content, starch content, and protein content; sorghum nixtamal moisture content was influenced by starch relative crystallinity, kernel moisture content, and abrasive hardness index. Pericarp removal was not strongly correlated with kernel characterization tests. Location and hybrid factors influenced most kernel characteristics and nixtamalization processing variables. Identifying sample growing locations would aid in screening samples for nixtamalization.